21243013132420 has 12 divisors (see below), whose sum is σ = 44610327578124. Its totient is φ = 8497205252960.

The previous prime is 21243013132339. The next prime is 21243013132423. The reversal of 21243013132420 is 2423131034212.

It can be written as a sum of positive squares in 2 ways, for example, as 15427314328644 + 5815698803776 = 3927762^2 + 2411576^2 .

It is not an unprimeable number, because it can be changed into a prime (21243013132423) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 531075328291 + ... + 531075328330.

It is an arithmetic number, because the mean of its divisors is an integer number (3717527298177).

Almost surely, 2^{21243013132420} is an apocalyptic number.

21243013132420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21243013132420 is an abundant number, since it is smaller than the sum of its proper divisors (23367314445704).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21243013132420 is a wasteful number, since it uses less digits than its factorization.

21243013132420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1062150656630 (or 1062150656628 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 28.

Adding to 21243013132420 its reverse (2423131034212), we get a palindrome (23666144166632).

The spelling of 21243013132420 in words is "twenty-one trillion, two hundred forty-three billion, thirteen million, one hundred thirty-two thousand, four hundred twenty".